Severity Rating: CriticalRevision Note: V1.1 (March 24, 2017): Bulletin published.Summary: This security update resolves vulnerabilities in Microsoft Windows, Microsoft Office, Skype for Business, Silverlight and Microsoft Lync. The most serious of these vulnerabilities could allow remote code execution if a user either visits a specially crafted website or opens a specially crafted document. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights.